U.S. Pat. No. 4,482,347 discloses a peristaltic pump which, because of its compactness and simplicity of construction, and its precise, accurate, and reliable operation, is particularly suitable for medical use in a fluid infusion or administration system or in a system for withdrawing fluids, such as wound, urine, pleura, or other drainage systems. The pump includes a series of bearing assemblies each having concentric inner and outer members capable of free rotation with respect to each other. The inner members are concentrically mounted upon a power-driven shaft with the centers of the inner members equidistant from the axis of the shaft and spaced at uniform angular distances thereabout to describe a helix about the axis of the drive shaft. A resilient tube extends along a line parallel with the shaft and is supported by a platen so that the tube is sequentially compressed by each of the outer bearing members of the series, thereby driving fluid through the resilient tube. A thin elastomeric membrane is interposed between the outer bearing members and the tube with the membrane in continuous contact with the tube during pump operation.
Such a pump is of positive action in its operation and is capable of generating substantial outlet pressures. While maximum discharge pressure may be controlled by simply discontinuing pump operation, situations exist in arthroscopic surgery and other medical and non-medical operations where interrupting pump operation, and the resultant decreases in pressure which then occur, are undesirable. What is instead needed is some means that operates independent of flow rate for insuring that a selected maximum discharge pressure is not exceeded. A further objective would be to attain such control over maximum outlet pressure while at the same time providing a unit which is simple and reliable in operation, is relatively compact, and utilizes relatively inexpensive tubing that may be economically discarded after a single interval of use.
Other types of peristaltic pumps are disclosed in the references cited in the aforementioned patent and are further represented by U.S. Pat. Nos. 4,373,525, 3,990,444, 3,542,491, and 4,029,441. U.S. Pat. No. 4,373,525 discloses a peristaltic pump with slidable fingers that engage a tube supported by a spring-loaded pressure plate, with the addition of a pivotal arm having "pressing parts" at its opposite ends for detecting pressure changes and triggering a suitable alarm; U.S. Pat. No. 3,990,444 ws a pump having a tube similarly supported by a spring-loaded pressure plate and with multiple rollers carried by a wheel that rotates in the same plane as the tubing; U.S. Pat. No. 3,542,491 discloses a pump also having rollers that are moved along a section of resilient tubing to drive fluid through that tubing; U.S. Pat. No. 4,029,441 discloses tubing formed by a folding operation which is held in place by jaws and saddle elements to insure a desired pumping action by rollers as they are advanced along the tube.